Function readUntil

cli/cliui/prompt.go:189–208

readUntil the first occurrence of delim in the input, returning a string containing the data up to and including the delimiter. Unlike `bufio`, it only reads until the delimiter and no further bytes. If readUntil encounters an error before finding a delimiter, it returns the data read before the err

(r io.Reader, delim byte)

// before the error and the error itself (often io.EOF). readUntil returns err != nil if and only if
// the returned data does not end in delim.
func readUntil(r io.Reader, delim byte) (string, error) {
	var (
		have []byte
		b    = make([]byte, 1)
	)
	for {
		n, err := r.Read(b)
		if n > 0 {
			have = append(have, b[0])
			if b[0] == delim {
				// match `bufio` in that we only return non-nil if we didn't find the delimiter,
				// regardless of whether we also erred.
				return string(have), nil
			}
		}
		if err != nil {
			return string(have), err
		}
	}
}

// readSecretInput reads secret input from the terminal rune-by-rune,
// masking each character with an asterisk.